Home » Ask & Discuss » Mathematics. » Analytical Geometry « Back to Discussion

Analytical Geometry

Cool goIITian

Joined:	1 Dec 2007
Post:	50

14 Jan 2008 08:16:33 IST

0 People liked this

528

circles

None

the equation of tangents drawn from the origin to the circle x*2+y*2-2rx-2hy+h*2=0
are:

Share this article on:

Comments (2)

sowjanya gudipati

Cool goIITian

Joined: 13 Oct 2007

Posts: 75

14 Jan 2008 12:59:56 IST

Like 0 people liked this

Re:circles

Rahul Raghavendra

Blazing goIITian

Joined: 9 Jan 2008

Posts: 843

14 Jan 2008 13:17:18 IST

Like 1 people liked this

since eqn of circle is x^2+y^2-2rx-2hy+h^2=0

comparing it by standard eqn ,x^2+y^2+2gx+2fy+c=0

we get

it's centre as (r,h) and radius as r

now ,let the eqn of tangent be y=mx+c.

since it is passing through origin ,eqn will reduce to y=mx.

now

length of perpendicular from centre of circle to tangent = radius of circle.

(mr-h)/

1+m^2 =r.

therefore from this u obtain m=(h^2-r^2)/2rh

eqn of tangent will be y={(h^2-r^2)/2rh}x

rate me if correct

Quick Reply

Reply

	Some HTML allowed.
	Keep your comments above the belt or risk having them deleted.
	Signup for a avatar to have your pictures show up by your comment
	If Members see a thread that violates the Posting Rules, bring it to the attention of the Moderator Team

Free Sign Up!

Preparing for IIT-JEE ?

Arihant Revision Package for IIT JEE - Books, Practice Tests + Rank Predictor

@ INR 1,995/-

For Quick Info

Find Posts by Topics

Physics.

Topics

9401

20093

3672

2186

7618

2827

2638

Mathematics.

Chemistry.

Biology

Institutes

Parents

Board

Fun Zone